# testing the std
import numpy
data = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
print("straight:", numpy.std(numpy.gradient(data)))

data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]
print("increase:", numpy.std(numpy.gradient(data)))

data = [1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2]
print("small shake:", numpy.std(numpy.gradient(data)))

data = [1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10]
print("big shake:", numpy.std(numpy.gradient(data)))
